<?php

// +----------------------------------------------------------------------

// | ThinkPHP [ WE CAN DO IT JUST THINK IT ]

// +----------------------------------------------------------------------

// | Copyright (c) 2006-2013 http://thinkphp.cn All rights reserved.

// +----------------------------------------------------------------------

// | Licensed ( http://www.apache.org/licenses/LICENSE-2.0 )

// +----------------------------------------------------------------------

// | Author: liu21st <liu21st@gmail.com>

// +----------------------------------------------------------------------

namespace Think\Db\Driver;

use Think\Db;

defined('THINK_PATH') or exit();

/**

 * PDO数据库驱动 

 */

class Pdo extends Db{



    protected $PDOStatement = null;

    private   $table        = '';



    /**

     * 架构函数 读取数据库配置信息

     * @access public

     * @param array $config 数据库配置数组

     */

    public function __construct($config=''){

        if(!empty($config)) {

            $this->config   =   $config;

            if(empty($this->config['params'])) {

                $this->config['params'] =   array();

            }

        }



    }



    /**

     * 连接数据库方法

     * @access public

     */

    public function connect($config='',$linkNum=0) {

        if ( !isset($this->linkID[$linkNum]) ) {

            if(empty($config))  $config =   $this->config;

            if($this->pconnect) {

                $config['params'][\PDO::ATTR_PERSISTENT] = true;

            }

            //$config['params'][PDO::ATTR_CASE] = C("DB_CASE_LOWER")?PDO::CASE_LOWER:PDO::CASE_UPPER;

            try{

                $this->linkID[$linkNum] = new \PDO( $config['dsn'], $config['username'], $config['password'],$config['params']);

            }catch (\PDOException $e) {

                E($e->getMessage());

            }

            // 因为PDO的连接切换可能导致数据库类型不同，因此重新获取下当前的数据库类型

            $this->dbType = $this->_getDsnType($config['dsn']);

            if(in_array($this->dbType,array('MSSQL','ORACLE','IBASE','OCI'))) {

                // 由于PDO对于以上的数据库支持不够完美，所以屏蔽了 如果仍然希望使用PDO 可以注释下面一行代码

                E('由于目前PDO暂时不能完美支持'.$this->dbType.' 请使用官方的'.$this->dbType.'驱动');

            }

            $this->linkID[$linkNum]->exec('SET NAMES '.C('DB_CHARSET'));

            // 标记连接成功

            $this->connected    =   true;

            // 注销数据库连接配置信息

            if(1 != C('DB_DEPLOY_TYPE')) unset($this->config);

        }

        return $this->linkID[$linkNum];

    }



    /**

     * 释放查询结果

     * @access public

     */

    public function free() {

        $this->PDOStatement = null;

    }



    /**

     * 执行查询 返回数据集

     * @access public

     * @param string $str  sql指令

     * @param array $bind 参数绑定

     * @return mixed

     */

    public function query($str,$bind=array()) {

        $this->initConnect(false);

        if ( !$this->_linkID ) return false;

        $this->queryStr = $str;

        if(!empty($bind)){

            $this->queryStr     .=   '[ '.print_r($bind,true).' ]';

        }        

        //释放前次的查询结果

        if ( !empty($this->PDOStatement) ) $this->free();

        N('db_query',1);

        // 记录开始执行时间

        G('queryStartTime');

        $this->PDOStatement = $this->_linkID->prepare($str);

        if(false === $this->PDOStatement)

            E($this->error());

        // 参数绑定

        $this->bindPdoParam($bind);

        $result =   $this->PDOStatement->execute();

        $this->debug();

        if ( false === $result ) {

            $this->error();

            return false;

        } else {

            return $this->getAll();

        }

    }



    /**

     * 执行语句

     * @access public

     * @param string $str  sql指令

     * @param array $bind 参数绑定

     * @return integer

     */

    public function execute($str,$bind=array()) {

        $this->initConnect(true);

        if ( !$this->_linkID ) return false;

        $this->queryStr = $str;

        if(!empty($bind)){

            $this->queryStr     .=   '[ '.print_r($bind,true).' ]';

        }        

        $flag = false;

        if($this->dbType == 'OCI') {

            if(preg_match("/^\s*(INSERT\s+INTO)\s+(\w+)\s+/i", $this->queryStr, $match)) {

                $this->table = C("DB_SEQUENCE_PREFIX").str_ireplace(C("DB_PREFIX"), "", $match[2]);

                $flag = (boolean)$this->query("SELECT * FROM user_sequences WHERE sequence_name='" . strtoupper($this->table) . "'");

            }

        }

        //释放前次的查询结果

        if ( !empty($this->PDOStatement) ) $this->free();

        N('db_write',1);

        // 记录开始执行时间

        G('queryStartTime');

        $this->PDOStatement = $this->_linkID->prepare($str);

        if(false === $this->PDOStatement) {

            E($this->error());

        }

        // 参数绑定

        $this->bindPdoParam($bind);        

        $result = $this->PDOStatement->execute();

        $this->debug();

        if ( false === $result) {

            $this->error();

            return false;

        } else {

            $this->numRows = $this->PDOStatement->rowCount();

            if($flag || preg_match("/^\s*(INSERT\s+INTO|REPLACE\s+INTO)\s+/i", $str)) {

                $this->lastInsID = $this->getLastInsertId();

            }

            return $this->numRows;

        }

    }



    /**

     * 参数绑定

     * @access protected

     * @return void

     */

    protected function bindPdoParam($bind){

        // 参数绑定

        foreach($bind as $key=>$val){

            if(is_array($val)){

              array_unshift($val,$key);

            }else{

              $val  = array($key,$val);

            }

            call_user_func_array(array($this->PDOStatement,'bindParam'),$val);

        }      

    }



    /**

     * 启动事务

     * @access public

     * @return void

     */

    public function startTrans() {

        $this->initConnect(true);

        if ( !$this->_linkID ) return false;

        //数据rollback 支持

        if ($this->transTimes == 0) {

            $this->_linkID->beginTransaction();

        }

        $this->transTimes++;

        return ;

    }



    /**

     * 用于非自动提交状态下面的查询提交

     * @access public

     * @return boolen

     */

    public function commit() {

        if ($this->transTimes > 0) {

            $result = $this->_linkID->commit();

            $this->transTimes = 0;

            if(!$result){

                $this->error();

                return false;

            }

        }

        return true;

    }



    /**

     * 事务回滚

     * @access public

     * @return boolen

     */

    public function rollback() {

        if ($this->transTimes > 0) {

            $result = $this->_linkID->rollback();

            $this->transTimes = 0;

            if(!$result){

                $this->error();

                return false;

            }

        }

        return true;

    }



    /**

     * 获得所有的查询数据

     * @access private

     * @return array

     */

    private function getAll() {

        //返回数据集

        $result =   $this->PDOStatement->fetchAll(\PDO::FETCH_ASSOC);

        $this->numRows = count( $result );

        return $result;

    }



    /**

     * 取得数据表的字段信息

     * @access public

     */

    public function getFields($tableName) {

        $this->initConnect(true);

        if(C('DB_DESCRIBE_TABLE_SQL')) {

            // 定义特殊的字段查询SQL

            $sql   = str_replace('%table%',$tableName,C('DB_DESCRIBE_TABLE_SQL'));

        }else{

            switch($this->dbType) {

                case 'MSSQL':

                case 'SQLSRV':

                    $sql   = "SELECT   column_name as 'Name',   data_type as 'Type',   column_default as 'Default',   is_nullable as 'Null'

        FROM    information_schema.tables AS t

        JOIN    information_schema.columns AS c

        ON  t.table_catalog = c.table_catalog

        AND t.table_schema  = c.table_schema

        AND t.table_name    = c.table_name

        WHERE   t.table_name = '$tableName'";

                    break;

                case 'SQLITE':

                    $sql   = 'PRAGMA table_info ('.$tableName.') ';

                    break;

                case 'ORACLE':

                case 'OCI':

                    $sql   = "SELECT a.column_name \"Name\",data_type \"Type\",decode(nullable,'Y',0,1) notnull,data_default \"Default\",decode(a.column_name,b.column_name,1,0) \"pk\" "

                      ."FROM user_tab_columns a,(SELECT column_name FROM user_constraints c,user_cons_columns col "

                      ."WHERE c.constraint_name=col.constraint_name AND c.constraint_type='P' and c.table_name='".strtoupper($tableName)

                      ."') b where table_name='".strtoupper($tableName)."' and a.column_name=b.column_name(+)";

                    break;

                case 'PGSQL':

                    $sql   = 'select fields_name as "Name",fields_type as "Type",fields_not_null as "Null",fields_key_name as "Key",fields_default as "Default",fields_default as "Extra" from table_msg('.$tableName.');';

                    break;

                case 'IBASE':

                    break;

                case 'MYSQL':

                default:

                    $sql   = 'DESCRIBE '.$tableName;//备注: 驱动类不只针对mysql，不能加``

            }

        }

        $result = $this->query($sql);

        $info   =   array();

        if($result) {

            foreach ($result as $key => $val) {

                $val            =   array_change_key_case($val);

                $val['name']    =   isset($val['name'])?$val['name']:"";

                $val['type']    =   isset($val['type'])?$val['type']:"";

                $name           =   isset($val['field'])?$val['field']:$val['name'];

                $info[$name]    =   array(

                    'name'    => $name ,

                    'type'    => $val['type'],

                    'notnull' => (bool)(((isset($val['null'])) && ($val['null'] === '')) || ((isset($val['notnull'])) && ($val['notnull'] === ''))), // not null is empty, null is yes

                    'default' => isset($val['default'])? $val['default'] :(isset($val['dflt_value'])?$val['dflt_value']:""),

                    'primary' => isset($val['key'])?strtolower($val['key']) == 'pri':(isset($val['pk'])?$val['pk']:false),

                    'autoinc' => isset($val['extra'])?strtolower($val['extra']) == 'auto_increment':(isset($val['key'])?$val['key']:false),

                );

            }

        }

        return $info;

    }



    /**

     * 取得数据库的表信息

     * @access public

     */

    public function getTables($dbName='') {

        if(C('DB_FETCH_TABLES_SQL')) {

            // 定义特殊的表查询SQL

            $sql   = str_replace('%db%',$dbName,C('DB_FETCH_TABLES_SQL'));

        }else{

            switch($this->dbType) {

            case 'ORACLE':

            case 'OCI':

                $sql   = 'SELECT table_name FROM user_tables';

                break;

            case 'MSSQL':

            case 'SQLSRV':

                $sql   = "SELECT TABLE_NAME FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_TYPE = 'BASE TABLE'";

                break;

            case 'PGSQL':

                $sql   = "select tablename as Tables_in_test from pg_tables where  schemaname ='public'";

                break;

            case 'IBASE':

                // 暂时不支持

                E(L('_NOT_SUPPORT_DB_').':IBASE');

                break;

            case 'SQLITE':

                $sql   = "SELECT name FROM sqlite_master WHERE type='table' "

                         . "UNION ALL SELECT name FROM sqlite_temp_master "

                         . "WHERE type='table' ORDER BY name";

                 break;

            case 'MYSQL':

            default:

                if(!empty($dbName)) {

                   $sql    = 'SHOW TABLES FROM '.$dbName;

                }else{

                   $sql    = 'SHOW TABLES ';

                }

            }

        }

        $result = $this->query($sql);

        $info   =   array();

        foreach ($result as $key => $val) {

            $info[$key] = current($val);

        }

        return $info;

    }



    /**

     * limit分析

     * @access protected

     * @param mixed $lmit

     * @return string

     */

    protected function parseLimit($limit) {

        $limitStr    = '';

        if(!empty($limit)) {

            switch($this->dbType){

                case 'PGSQL':

                case 'SQLITE':

                    $limit  =   explode(',',$limit);

                    if(count($limit)>1) {

                        $limitStr .= ' LIMIT '.$limit[1].' OFFSET '.$limit[0].' ';

                    }else{

                        $limitStr .= ' LIMIT '.$limit[0].' ';

                    }

                    break;

                case 'MSSQL':

                case 'SQLSRV':

                    break;

                case 'IBASE':

                    // 暂时不支持

                    break;

                case 'ORACLE':

                case 'OCI':

                    break;

                case 'MYSQL':

                default:

                    $limitStr .= ' LIMIT '.$limit.' ';

            }

        }

        return $limitStr;

    }



    /**

     * 字段和表名处理

     * @access protected

     * @param string $key

     * @return string

     */

    protected function parseKey(&$key) {

        if($this->dbType=='MYSQL'){

            $key   =  trim($key);

            if(!preg_match('/[,\'\"\*\(\)`.\s]/',$key)) {

               $key = '`'.$key.'`';

            }

            return $key;            

        }else{

            return parent::parseKey($key);

        }



    }



    /**

     * 关闭数据库

     * @access public

     */

    public function close() {

        $this->_linkID = null;

    }



    /**

     * 数据库错误信息

     * 并显示当前的SQL语句

     * @access public

     * @return string

     */

    public function error() {

        if($this->PDOStatement) {

            $error = $this->PDOStatement->errorInfo();

            $this->error = $error[1].':'.$error[2];

        }else{

            $this->error = '';

        }

        if('' != $this->queryStr){

            $this->error .= "\n [ SQL语句 ] : ".$this->queryStr;

        }

        trace($this->error,'','ERR');

        return $this->error;

    }



    /**

     * SQL指令安全过滤

     * @access public

     * @param string $str  SQL指令

     * @return string

     */

    public function escapeString($str) {

         switch($this->dbType) {

            case 'PGSQL':

            case 'MSSQL':

            case 'SQLSRV':

            case 'MYSQL':

                return addslashes($str);

            case 'IBASE':                

            case 'SQLITE':

            case 'ORACLE':

            case 'OCI':

                return str_ireplace("'", "''", $str);

        }

    }



    /**

     * value分析

     * @access protected

     * @param mixed $value

     * @return string

     */

    protected function parseValue($value) {

        if(is_string($value)) {

            $value =  strpos($value,':') === 0 ? $this->escapeString($value) : '\''.$this->escapeString($value).'\'';

        }elseif(isset($value[0]) && is_string($value[0]) && strtolower($value[0]) == 'exp'){

            $value =  $this->escapeString($value[1]);

        }elseif(is_array($value)) {

            $value =  array_map(array($this, 'parseValue'),$value);

        }elseif(is_bool($value)){

            $value =  $value ? '1' : '0';

        }elseif(is_null($value)){

            $value =  'null';

        }

        return $value;

    }



    /**

     * 获取最后插入id

     * @access public

     * @return integer

     */

    public function getLastInsertId() {

         switch($this->dbType) {

            case 'PGSQL':

            case 'SQLITE':

            case 'MSSQL':

            case 'SQLSRV':

            case 'IBASE':

            case 'MYSQL':

                return $this->_linkID->lastInsertId();

            case 'ORACLE':

            case 'OCI':

                $sequenceName = $this->table;

                $vo = $this->query("SELECT {$sequenceName}.currval currval FROM dual");

                return $vo?$vo[0]["currval"]:0;

        }

    }

}